A MEK inhibitor is a chemical or drug that inhibits the mitogen-activated protein kinase kinase enzymes MEK1 and/or MEK2. They can be used to affect the MAPK/ERK pathway which is often overactive in some cancers.
Hence MEK inhibitors have potential for treatment of some cancers, especially BRAF-mutated melanoma, and KRAS/BRAF mutated colorectal cancer.
Approved for clinical use
Trametinib (GSK1120212), FDA-approved to treat BRAF-mutated melanoma. Also studied in combination with BRAF inhibitor dabrafenib to treat BRAF-mutated melanoma.
Cobimetinib or XL518, approved by US FDA in Nov 2015 for use in combination with vemurafenib (Zelboraf(R)), for treatment of advanced melanoma with a BRAF V600E or V600K mutation.
In clinical trials
Binimetinib (MEK162), is currently in phase 3 clinical trials for ovarian cancer, BRAF mutant melanoma, and NRAS mutant melanoma.
Selumetinib, had a phase 2 clinical trial for non-small cell lung cancer (NSCLC) which demonstrated an improvement in PFS, and is now in phase III development in KRAS mutation
Readings and References
MEK inhibitors and their potential in the treatment of advanced melanoma: the advantages of combination therapy